Twisting or straightening mechanism



Jan- 21, 19.41- 7cs. E. NIGHTHART Erm. 2,229,517

TWISTING OR STRAIGHTENING MECHANISM GEORGE E. NIGHT/#IRT EDWARD M. WHEELEl? A ORNEY.

Jan. 2l, 1941.

G. E. NIGHTHART ETAL TWISTING OR STRAIGHTENING MECHANISM 6m.du

Filed May 16, 1938 u IIIIJ NHV Patented Jan. 2i, i941 TWISTING RSTRAIGHTENHNG RIECHANHSM George E. Nighthart and Edward M. Wheeler, New

Kensington, Pa., assignorsv to Aluminum Company of America, Pittsburgh,Pa., a corporation of Pennsylvania Application May 16, 1938, Serial No.208,110

g 3 Claims. (Cl. 153-78) 'Ihis invention relates to the straightening ofbars, shapes, and the like, which, after being given theircross-sectional conguration by rolling, extrusion, and like processes,are found to be warped, twisted, or skewed. More particularly, theinvention relates to straightening such products by applying to apre-formed shape a torsional force, suflicient to stress it beyond itselastic limit, at any desired point or points along the length of theshape. A

It is an object of this invention to provide an improved device for usein connection with material or shape-stretching machines to the end thatevery type of irregularity in such shapes may be satisfactorily andeiiiciently removed. It is another bject of the invention to provide ameans for `removing twists which extend only through a portion of thelength of a pre-formed shape, or twists which are not uniform. Thedevice of the invention, which is hereinafter termed a twisting head1 isdesigned to be used in conjunction with material stretchers equippedeither with a xed stretching head or with a rotating stretching headsuch as, for example, the type of mechanism shown in the copendingapplication, Serial No. 121,483, led January 21, 1937. The device of theinvention is adapted to be positioned I on the bed of such a stretchermechanism, and Vmay be moved to any desired position between the headand'tail stocks.

In the production of shapes or bars, or the like, particularly extrudedshapes, various types of deformity appear in the members as produced. Ofthe -common deformities, the most dimcult to remove are twists or skeweswhich are non-uniform throughout the length of the shape, and

twists or skewes which are oppositely disposed with respect to thelongitudinal axis of the shape. The invention is designed to efcientlyremove 40 such deformities with a minimum of handlin and the leastnumber of operations. t In order to describe and explain the inventionin terms of an actual installation, reference is hereinafter made to theaccompanying drawings, forming a part of this specification, in

which:

Figure 1 represents a side elevation of a twist. ing head, with portionsor the belt and gear housings brokenaway to more clearly show the modeof construction;

Figure 2 represents an end view of the same device with a portion of thegear housing broken away; l

` l1=igure3.isa sectional I elevationutaken `along I5 the line III-IIIof Figure 4; and

Figure 4 is a sectional elevation taken along the line IV-IV of Figure3.

The twisting head o f this invention is preferably mounted upon a bed Iof a stretcher mechanism along which it may be moved or trans- 5 latedthrough the medium of wheels 2 which are actuated by a suitablereversible motor 3, directly connected to said wheels by means of atrain of gears 4. When in proper position 1ongitudinally of a member orshape to be straight- 10 ened, the twisting or straightening head of theinvention is clamped to the bed I by means of clamp members 5 which arepivotally hinged at 6 to the frame l2 of the twisting head. In Figure 4the left-hand clamp 5 is illustrated in its J open position fortraveling along the bed, and the right-hand clamp is shown in engagementwith the bed I to secure the twistinghead in position with respect tothe bed. A shouldered screw 'I is suitably mounted for rotation, as by20 means of the hand wheel 8, in a journal member 9 which is pivotedupon the clamp 5 on a pin I0. The threads of the screw 1 cooperate withcomplementary threads in a bar member II which is oscillatably mountedin the frame I2, whereby 25 rotation of the screw 1 brings the clamp`5into clamping relationship with the underside of base l. A set screw I3is provided to adjustably x the clearance between the base I and theclamp 5 for longitudinal travel. 30

In Figures 3 and 4, the bar or shape to be straightened is grippedbetween suitably shaped jaws I4, which are designed to grip the shapewithout distorting the same. In Figure 4, a channel is shown in dottedlines in the central 35 position in vwhich the jaws will engage it. Eachjaw is mounted on a suitable screw4 I5, the threads of which cooperatewith internal threads in a sleeve I6. The sleeves I6 are provided withexternal threads which cooperate with comple- 40 mentary threads in xednuts I1. The sleeves I6 are rotated by gears' I8 mounted thereon and.cooperating with gears I9 ukeyed to a suitable shaft 20. The shaft 20 isdriven by a worm and worm wheel mechanism 2l, a hand wheel 22 be- 45 ingprovided for imparting rotation to the shaft 20. The upper and lowerjawsare simultaneously actuated by the common shaft 20, whereby rotation ofthe hand wheel 22 brings the jaws Il into engagement with the pre-formedshape to 50 grip the same, so that it is held at the center of rotationof the twisting head proper. A,

The entire jaw operating mechanism above described is rigidly mounted ona rotatable' slotted wheel 23, which is constructed in theA form of agear from which a section has been omitted so that pre-formed materialto be straightened may be inserted conveniently in the jaws I4 in aplane perpendicular to the plane of rotation of the slotted wheel 23.This omitted section will be hereinafter'termed the slot. The perimeterof the slotted wheel 23 is provided with a raised center portion 24constructed kin the form of suitable gear teeth, track surfaces 25 beingprovidedon either side of the raised center portion 24. The slottedwheel 23 is supported by a suitable number of rollers 26 which arerotatably mounted upon shafts 21 mounted in the frame I2, the rollers 26defining the center or path of rotation of the slotted wheel 23.

' 'I'Ihe gear teeth 24 :are preferably constructed as herring boneteeth, and engage complementary herring bone'pinlons 28 and 29, thelatter being` keyed -to opposi-tely disposed shafts carrying spur gears30. The pinions 28 and 29 are so positioned that the distance betweentheir points of engagement with the gear teeth 24 of the slotted wheelis greater than the width of the slot in the wheel 23. Since the shaftssupporting the two pinlons 28 and 29 are rotated through the medium of acommon gear 3| in engagement with gears 30, it will be seen that atleast one of the pinions 28 and 29 will Ialways be in engagementI withthe toothed surface 24 of the slotted Wheel 23 for all positions of thiswheel. Hence the slotted wheel may be driven in eitherdirection,regardless of the position of its slot. The drive pinion 3l, whichimparts rotation to the gears 30 and pinions 28`|and 29, is mounted upona shaft 33, which shaft has a suitable belt pulley 32 keyed thereto.Pulley 32 is belt-connected to a similar pulley secured to .theshaft ofa suitable reversible motor 34, which provides means for rota-ting theslotted wheel 23. In order that the slotted wheel may be definitely andselectively positioned with regard to the frame I2I a brake 35, actuatedby a solenoid 36, is mounted on the shaft of the motor 34. The motoris'also mounted on a platform 31 which is hingedly connected at 38 tothe main frame I2 of the twisting head, a pivotedl rod 39 passingthrough the platform 31 and adjustably secured to the platform 31, as bysuitable nuts 40 threaded on the rod 39, providing adjustable means forregulating the tension of the belt from the motor 34 to pulley 32.

In order to minimize any danger of accidental damage to a stretchingmachine employing one or vmore'of the twisting mechanisms of theinvention, bumper rods 4| Iare provided in the lower portion 'of frameI2. Springs 42 are positioned upon turned down portions of the rods 4I yand serve to cushion any shock received through possi-ble collisionbetween fa twisting head and other mechanisms, or head or tail stocks.

-In operation, one or more of the twisting heads, hereinabove described,is mounted on the bed of a stretcher mechanism between its head and tailstocks. The shape to be straightened is secured in the head and tailstocks, and the jaws I4 of the straightening or twisting head1 of theinvention are manipulated, through the medium of the hand wheel 22, intoposition to clamp or grip the shape to be straightened. Torsional stressis thereafterimparted to the clamped shape or section by means ofrotating the slotted wheel 23 in the proper direction to remove thetwist existing in the shape. `The introduction of this torsional stressmay occur either prior to or during .the longitudinal stretchingoperation, both modes of imparting torsional stress having been foundexceedingly satisfactory in practice.

The twisting head of lthe invention, which may be referred to as anintermedi-ate twisting head to distinguish the same from the tail orhead stocks of a stretching mechanism, either or both of which may bedesigned for rotation, is adapted to be used in conjunction withstretchers having a xed head or having a rotating head such as, forexample, that described in the copending application hereinbeforementioned. If the heads or tail and head stocks of the stretchermechanism, to which the intermediate twisting head of this invention hasbeen adapted, are both incapable of rotation, the intermediate head mayserve the additional useful purpose of rotating theend of a pre-formedshape after its opposite end has been clamped in the tail stock of the-stretcher mechanism, whereby the shape may be twisted into position tobe gripped by the head stock of the stretcher mechanism.

While the description of -this invention has been limited to a specificembodiment of the invention, it will be apparent that many modificationsthereof will present themselves to those skilled in this art, and it isthe intent that such modiiications are to be considered as having beencontemplated within the scope and spirit of the appended claims.

What is claimed is:

1. In a twisting mechanism for straightening bars and shapes, a frame, aplurality of rollers mounted in said frame, means adapted for rotationwithin a path defined by said rollers, clamping means mounted in saidrotatable means accessiblel to the insertion of a work-piece in a planeperpendicular to the plane of rotation, and means adapted to drive saidrotatable means at points spaced apart a distance greater than thedistance provided for the insertion of the work-piece, said clampingmeans being actuated from a common driving means, whereby .theWork-piece is centered at the center of rotation of said rotatablemeans.

2. In combination with a stretching machine, a twisting mechanism forstraightening bars and shapes, a frame ,.a plurality of rollers mountedin said frame, means adapted for rotation within a path 'defined by saidrollers, clamping means mounted in said rotatable means accessible tothe insertion of a work-piece in a plane perpendicular to the plane ofrotation, and means adapted to drive said rotatable means at pointsspaced apart a distance greater than the distance provided for theinsertion of the work-piece, said clamping means being actuated from acommon driving means, whereby the Work-piece is centered at the cen-terof rotation of said rotatable means.

3. In a twisting mechanism for straightening bars and shapes, a frame, aplurality of rollers mounted in said frame, means adapted for rotationwithin a path defined by said rollers, clamping means mounted in saidrotatable means accessible to lateral insertion of a-workpiece in aplane perpendicular -to the plane of rotation, and means adapted todrive said rotatable means, said clamping means being actuated from acommon independent driving means, whereby .the workpiece is centered atthe center of rotation of the rotatable means.

GEORGE E. NIGHTHART. EDWARD M. WHEELER.

